H2A.Z-nucleosomes are present in both euchromatin and heterochromatin and it has proven difficult to interpret their disparate roles in the context of their stability features. Using an in situ assay of nucleosome stability and DT40 cells expressing engineered forms of the histone variant we show that native H2A.
View Article and Find Full Text PDFObjective: Epigenetic mechanisms play regulatory roles in dental pulp stem cell (DPSC) differentiation. The molecules that modulate these mechanisms can be used to enhance DPSC differentiation in experimental studies and clinical applications. We investigated the combined effects of an epigenetic modulator enhancer of zeste homologue 2 inhibitor (EZH2i), trichostatin A (TSA), and 5-azacytidine (5-AZA) on the osteogenic differentiation of DPSCs.
View Article and Find Full Text PDFPeptide presentation by MHC class I and MHC class II molecules plays important roles in the regulation of the immune response. One factor in these displays is the density of antigen, which must exceed a critical threshold for the effective activation of T cells. Nonrandom distribution of MHC class I and class II has already been detected at the nanometer level and at higher hierarchical levels.
View Article and Find Full Text PDFThe roles and molecular interactions of polyamines (PAs) in the nucleus are not fully understood. Here their effect on nucleosome stability, a key regulatory factor in eukaryotic gene control, is reported, as measured in agarose embedded nuclei of H2B-GFP expressor HeLa cells. Nucleosome stability was assessed by quantitative microscopy [1,2] in situ, in close to native state of chromatin, preserving the nucleosome constrained topology of the genomic DNA.
View Article and Find Full Text PDFIn cancer therapy, immunogenic cell death eliminates tumor cells more efficiently than conventional apoptosis. During photodynamic therapy (PDT), some photosensitizer (PS) targeting lysosomes divert apoptosis to the immunologically more relevant necrosis-like cell death. Acridine orange (AO) is a PS targeting lysosome.
View Article and Find Full Text PDFPurpose: To observe and describe the anterior segment optical coherence tomography features of limbally localised non-malignant epithelial mass lesions METHODS: Thirteen patients (age: 66.9 ± 16.3 years) with conjunctival mass suggesting ocular surface squamous neoplasia with biomicroscopic examination were imaged using anterior segment ocular coherence tomography (anterior segment optical coherence tomography)/Cirrus HD-OCT, Model 4000, Carl Zeiss Meditec, Inc.
View Article and Find Full Text PDFIn most animals, the start of embryogenesis requires specific histones. In Drosophila linker histone variant BigH1 is present in early embryos. To uncover the specific role of this alternative linker histone at early embryogenesis, we established fly lines in which domains of BigH1 have been replaced partially or completely with that of H1.
View Article and Find Full Text PDFBackground: Presence of corneal cystine crystals is the main ocular manifestation of cystinosis, although controversial findings concerning the corneal layer with the highest density have been reported. The aim of this study was the analysis of the characteristics of crystal arrangement in different corneal layers and the assessment of corneal morphological changes with age.
Methods: A cross sectional study was carried out in three children and three adults who had nephropathic cystinosis and corneal cystine depositions.
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
View Article and Find Full Text PDFUnexpectedly, the widely used anticancer agents Cisplatin (Cis-Pt) and Daunorubicin (Dauno) exhibited cell type- and concentration-dependent synergy or antagonism in vitro. We attempted to interpret these effects in terms of the changes elicited by the drugs in the chromatin, the target held primarily responsible for the cytotoxicity of both agents. We measured the effect of Cis-Pt on the levels of Dauno in different cell compartments, the effect of Cis-Pt on Dauno-induced nucleosome eviction, and assessed the influence of Dauno on DNA platination in flow- and laser scanning cytometry as well as in laser ablation-inductively coupled plasma-mass spectrometry assays.
View Article and Find Full Text PDFThe restricted access of regulatory factors to their binding sites on DNA wrapped around the nucleosomes is generally interpreted in terms of molecular shielding exerted by nucleosomal structure and internucleosomal interactions. Binding of proteins to DNA often includes intercalation of hydrophobic amino acids into the DNA. To assess the role of constrained superhelicity in limiting these interactions, we studied the binding of small molecule intercalators to chromatin in close to native conditions by laser scanning cytometry.
View Article and Find Full Text PDFPurpose: To assess the validity of wide-field digital imaging (WFDI) and telemedicine-based screening compared with examination by binocular indirect ophthalmoscopy (BIO) and to present some of the results from the first five years of telemedicine-based screening in the Premature Eye Rescue Program in Hungary.
Methods: We performed a retrospective analysis in two periods that aimed to assess (a) the validity of retinal digital imaging and (b) routine bedside screening. The validity was assessed in two neonatal intensive care units (NICUs), one in the First Department of Paediatrics and the other in the Second Department of Obstetrics and Gynaecology, Semmelweis University.
Ocular mucous membrane pemphigoid (MMP) is a rare, immuno-mediated chronic progressive condition of the conjunctiva characterized by blisters developing from sub-epithelial tissue through disruption of the adhesions between the conjunctival epithelium and the sub-epithelium. Patients with ocular MMP, in many cases, develop profound conjunctival scarring and visual impairment. Furthermore, ocular MMP may lead to a progressive secondary corneal vascularization and to corneal opacification.
View Article and Find Full Text PDFSince 2017, the nomenclature of Fusarium, Acremonium and Sarocladium species have changed, as these morphologically homogeneous, but phylogenetically heterogeneous species and species complexes may be differentiated using MALDI-TOF MS examination, analyzing nucleotic sequences. This resulted in taxonomical changes. We summarize the clinical course, diagnostic and therapeutic options of keratitis caused by Fusarium and Sarocladium.
View Article and Find Full Text PDFMolecular combing and gel electrophoretic studies revealed endogenous nicks with free 3'OH ends at ∼100 kb intervals in the genomic DNA (gDNA) of unperturbed and G1-synchronized Saccharomyces cerevisiae cells. Analysis of the distribution of endogenous nicks by Nick ChIP-chip indicated that these breaks accumulated at active RNA polymerase II (RNAP II) promoters, reminiscent of the promoter-proximal transient DNA breaks of higher eukaryotes. Similar periodicity of endogenous nicks was found within the ribosomal rDNA cluster, involving every ∼10th of the tandemly repeated 9.
View Article and Find Full Text PDFBone morphogenetic protein-2 (BMP-2), is a potential factor to enhance osseointegration of dental implants. However, the appropriate cellular system to investigate the osteogenic effect of BMP-2 in vitro in a standardized manner still needs to be defined. The aim of this study was to examine the effect of BMP-2 on the cell proliferation and osteogenic differentiation of human osteogenic progenitors of various origins: dental pulp stem cells (DPSC), human osteosarcoma cell line (Saos-2) and human embryonic palatal mesenchymal cell line (HEPM).
View Article and Find Full Text PDFCurrent approaches have limitations in providing insight into the functional properties of particular nucleosomes in their native molecular environment. Here we describe a simple and powerful method involving elution of histones using intercalators or salt, to assess stability features dependent on DNA superhelicity and relying mainly on electrostatic interactions, respectively, and measurement of the fraction of histones remaining chromatin-bound in the individual nuclei using histone type- or posttranslational modification- (PTM-) specific antibodies and automated, quantitative imaging. The method has been validated in H3K4me3 ChIP-seq experiments, by the quantitative assessment of chromatin loop relaxation required for nucleosomal destabilization, and by comparative analyses of the intercalator and salt induced release from the nucleosomes of different histones.
View Article and Find Full Text PDFWe summarize up-to-date diagnostic and treatment of infectious keratitis using literature data and some clinical examples. In the clinical practice, most commonly bacterial, herpetic, mycotic and acanthamoeba keratitis occur. Beside slitlamp examination, for diagnostic purpose, we analyse corneal sensitivity, perform in vivo confocal microscopy, polymerase-chain-reaction (PCR), in vitro culture and histological examination of the corneal sample.
View Article and Find Full Text PDFEur J Ophthalmol
January 2017
Purpose: To report on the presence of 4 different structures visualized by confocal microscopy in patients whose clinical presentation suggested infection by Acanthamoeba.
Methods: Data and charts of 28 consecutive patients were analyzed in a retrospective study. Four types of structures were recognized by confocal microscopy performed with HRT II Rostock Cornea Module: trophozoites, double-walled cysts, signet rings, and bright spots.
In dental implantation missing tooth or teeth are replaced by artificial root. To reduce the time required for the integration newest trends are the enhancement of bone formation around the implant by bioactive molecules, growth factors. Such a molecule is bone morphogenetic protein-2 (BMP-2) accepted by US Food and Drug Administration (FDA).
View Article and Find Full Text PDFAfter a thourough development phase, a new system of health financing was introduced in Hungary in 1993. One of the cornerstones of the system was the financing of acute hospital care through Diagnosis-Related Groups (DRGs). This method was part of a comprehensive healthcare model, elaborated and published around 1990 by experts of Gyógyinfok, a public institute.
View Article and Find Full Text PDFIntroduction: Retinopathy of prematurity is a leading cause of childhood blindness around the world.
Aim: The Department of Ophthalmology at the Semmelweis University and the Peter Cerny Neonatal Emergency and Ambulance Service started an innovative Premature Eye Rescue Program to reduce the non-essential transport of premature babies suffering from retinopathy of prematurity.
Method: During the first 5 years 186 eyes of 93 premature babies were treated at the bedside with stage 3 retinopathy of prematurity in the primary hospitals.
Retinoids are morphogens and have been implicated in cell fate commitment of embryonic stem cells (ESCs) to neurons. Their effects are mediated by RAR and RXR nuclear receptors. However, transcriptional cofactors required for cell and gene-specific retinoid signaling are not known.
View Article and Find Full Text PDFBackground And Aim: Long-term care (LTC) in Hungary is provided in four major ways: day care, nursing, chronic care, and rehabilitation. The aim of this study was to explore the financing of LTC in Hungary, with a disease-specific focus on rheumatoid arthritis (RA) patients.
Data And Methods: Data were derived from the National Health Insurance Fund Administration (NHIFA).